This invention relates to pipe couplings, and more particularly to pipe couplings particularly useful for repairing damaged portions of unthreaded plastic pipe plumbing systems.
Plastic pipes have become widely used in sprinkler and other plumbing systems because of their low cost and ease of connection and repair. Such pipes are commonly referred to as PVC pipes because they are generally formed of some type of polyvinyl chloride composition. They are typically joined without threading by applying an adhesive such as a solvent cement to the ends of the pipes and then slipping the ends into a smooth bore coupling.
Various improved couplings have been previously disclosed which are particularly adapted for facilitating the use of unthreaded plastic pipe systems; e.g. see Applicant's U.S. Pat. Nos. 3,857,588; 3,971,574; 4,035,002; 4,103,943.